Hospira Inc. reports it has received a warning letter from the U.S. Food and Drug Administration over quality problems at its Costa Rican plant that makes the majority of its infusion pumps.

According to the warning, the FDA cited a number of ongoing problems with the companyâ€™s Plum brand infusion pump, which the company recalled in February 2011 because of problems with its alarm. Reports of alarm failures continued to come in even after a supplier redesigned the part.

The warning does not restrict productions or product shipments from the plant in La Aurora de Heredia, Costa Rica.

A Hospira spokesperson said the company was switching alarm components for the pump and plans to complete the process by early 2013. The company has been working to resolve the problem at some of its plants for several years.

Hospira, based in Lake Forest, Illinois, said in February that it had resumed production of injectable drugs at its Rocky Mount, North Carolina, plant, after a maintenance shutdown. None of the problems resulted in shortages of anesthesia or any other drugs.